1. Field of the Invention
The present invention relates to an image reading device and an image reading method that are used for reading of a printed material, a reading area display device, a reading area display method, and a program.
2. Description of the Related Art
In the field of printing, a correspondence relationship between colors of manuscript image data and a printed material on which an image has been printed on the basis of the manuscript image data is obtained in order to evaluate color reproduction of the printed material on which the image has been printed on the basis of the manuscript image data. This correspondence relationship is obtained by comparing a color distribution of the manuscript image data with a color distribution of read image data obtained by reading the printed material using a scanner (reading unit).
In recent years, in a case where reading of a printed material is performed using a scanner, a size of the printed material may be larger than a reading range (also referred to as a reading area) in which the printed material can be read by the scanner. In this case, generally, the printed material is divided into a plurality of areas, each area is read by the scanner to acquire area read image data for each area, and then pieces of the area read image data are combined to obtain read image data of the entire printed material.
JP2012-160957A discloses an image reading device that compares degrees of inclination between area image data read for the first time and area image data read for the second time and subsequent times to prevent a blank portion from being generated in an image based on the read image data after combination.
JP2010-068381A discloses an image reading device that combines area read image data for each area using a cover sheet on which a grid indicating position information of the plurality of areas described above is printed with a dropout color. The image reading device of JP2010-068381A performs switching between two types of illumination lights with which an image including a dropout color and an image not including the dropout color can be acquired when causing the cover sheet to overlap the printed material and then reading each area using a scanner. Thus, the image reading device of JP2010-068381A can acquire area read image data for each area including the grid printed with the dropout color and area read image data for each area not including the grid. The image reading device of JP2010-068381A combines the area read image data of each area not including the grid on the basis of the position information acquired from the area read image data of each area including the grid to obtain the read image data of the entire printed material.
According to this image reading device described in JP2012-160957A and JP2010-068381A, even in a case where a size of the printed material is larger than the reading range of the scanner, the printed material is divided into a plurality of areas and each area is read by the scanner so as to obtain read image data of the entire printed material. Thus, it is possible to analyze the read image data of the printed material to obtain a color distribution, and a correspondence relationship between colors of the manuscript image data and the printed material is obtained by comparing a color distribution of the read image data with a color distribution of the manuscript image data.